diff options
| -rw-r--r-- | include/osmocom/gsm/gsm0808_utils.h | 2 | ||||
| -rw-r--r-- | src/gsm/gsm0808_utils.c | 54 | ||||
| -rw-r--r-- | src/gsm/libosmogsm.map | 1 |
3 files changed, 57 insertions, 0 deletions
diff --git a/include/osmocom/gsm/gsm0808_utils.h b/include/osmocom/gsm/gsm0808_utils.h index b5106447..cb53e0c0 100644 --- a/include/osmocom/gsm/gsm0808_utils.h +++ b/include/osmocom/gsm/gsm0808_utils.h @@ -73,3 +73,5 @@ int gsm0808_dec_cell_id_list(struct gsm0808_cell_id_list *cil, const uint8_t *elem, uint8_t len); int gsm0808_chan_type_to_speech_code(uint8_t perm_spch); +int gsm0808_speech_codec_from_chan_type(struct gsm0808_speech_codec *sc, + uint8_t perm_spch); diff --git a/src/gsm/gsm0808_utils.c b/src/gsm/gsm0808_utils.c index 64ffec4e..00da04b0 100644 --- a/src/gsm/gsm0808_utils.c +++ b/src/gsm/gsm0808_utils.c @@ -682,4 +682,58 @@ int gsm0808_chan_type_to_speech_codec(uint8_t perm_spch) return -EINVAL; } +/*! \brief Extrapolate a speech codec field from a given permitted speech + * parameter (channel type). + * \param[out] sc Caller provided memory to store the resulting speech codec + * \param[in] perm_spch value that is used to derive the speech codec info + * (see also: enum gsm0808_speech_codec_type in gsm0808_utils.h) + * \returns zero when successful; negative on error */ +int gsm0808_speech_codec_from_chan_type(struct gsm0808_speech_codec *sc, + uint8_t perm_spch) +{ + int rc; + + memset(sc, 0, sizeof(*sc)); + + /* Determine codec type */ + rc = gsm0808_chan_type_to_speech_codec(perm_spch); + if (rc < 0) + return -EINVAL; + sc->type = (uint8_t) rc; + + /* Depending on the speech codec type, pick a default codec + * configuration that exactly matches the configuration on the + * air interface. */ + switch (sc->type) { + case GSM0808_SCT_FR3: + sc->cfg = GSM0808_SC_CFG_DEFAULT_FR_AMR; + break; + case GSM0808_SCT_FR4: + sc->cfg = GSM0808_SC_CFG_DEFAULT_OFR_AMR_WB; + break; + case GSM0808_SCT_FR5: + sc->cfg = GSM0808_SC_CFG_DEFAULT_FR_AMR_WB; + break; + case GSM0808_SCT_HR3: + sc->cfg = GSM0808_SC_CFG_DEFAULT_HR_AMR; + break; + case GSM0808_SCT_HR4: + sc->cfg = GSM0808_SC_CFG_DEFAULT_OHR_AMR_WB; + break; + case GSM0808_SCT_HR6: + sc->cfg = GSM0808_SC_CFG_DEFAULT_OHR_AMR; + break; + default: + /* Note: Not all codec types specify a default setting, + * in this case, we just set the field to zero. */ + sc->cfg = 0; + } + + /* Tag all codecs as "Full IP" + * (see als 3GPP TS 48.008 3.2.2.103) */ + sc->fi = true; + + return 0; +} + /*! @} */ diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map index ccc5b9a4..36cba391 100644 --- a/src/gsm/libosmogsm.map +++ b/src/gsm/libosmogsm.map @@ -163,6 +163,7 @@ gsm0808_dec_encrypt_info; gsm0808_enc_cell_id_list; gsm0808_dec_cell_id_list; gsm0808_convert_to_speech_codec_type; +gsm0808_extrapolate_speech_codec; gsm0858_rsl_ul_meas_enc; |